Jantzen Wax Coil or Mundorf M-Coil CFC

12 gauge all the way. I have tried 16 and 12 gauge, and the 12 sounded better in every possible way. The difference in cost is nothing for an $18k speaker :)

I think anything over 12 gauge might be overkill, but then again I have seen others claim otherwise. Mundorf has a 70mm wide inductor, comes out as 10 gauge which might be a good option. 

Jantzen 10 gauges are thicker foils, which I would stay away from. 

You have some very nice speakers, hopefully I get to listen to pair one of these days. 

I am in Southern Westchester County, NY, on the off-chance you are within a drivable distance.

I would definitely take you up on that offer, but I am on the other side of the country.... Los Angeles. 

I hope you can get your crossover figured out 🙏

Those speakers deserve a good one.  

If the Mundorf coils with paper (specifically MCoil VLCU Copper Foil Paper) is available in 9 AWG (and assuming not too thick of a conductor at 9 AWG) while the Duelund CAST inductors are 12 AWG, I wonder which of the two sounds better, and how much better, in the bass and perhaps also midrange sections.  I know Duelund is more costly but am not terribly sensitive to cost unless the improvement is minor, and there may be a long wait time for Duelund inductors.  A friend checked recently and was told close to a year.

You should be fine with the Mundorf honestly.

If the wait was say a month, that would be a different thing, but a year is unreasonable.

The 70mm foil should be perfect for your application, just make sure to also upgrade the wiring on the inside of the speakers.